Sanitary napkin



July 28, 1959 K. J. HARWOOD SANITARY NAPKIN 2 Sheets-Sheet 1 OriginalFiled July 14. 1955 I A fibrous Hait /vial INVENTOR. iidenneihd'flarwoodBY I 50%, 2104/ July 28, 1959 K. J. HARWOOD 2,396,627

' SANITARY NAPKIN Original Filed July 14. 1955 2 Sheets-Sheet 2INVENTOR.

United States Patent SANITARY NAPKIN Kenneth J. Harwood, Neenah, Wis.,assignor to KimberlysClark Corporation, Neenah, Wis., a corporation ofDelaware 12 Claims. (Cl. 128-290) The present invention relatesgenerally to absorbent pads, and is particularly directed to an improvedform of sanitary napkin.

In the manufacture of absorbent pads, such as sanitary napkins, one ofthe major problems is proper control ofthe flow of the fluids absorbedby the pad, so that such fluid will be prevented from striking throughthe pad and so that maximum usage of the absorbency of the pad can berealized. It has been found that one of the most eifective means forpreventing strike through and for distributing the absorbed fluidthroughout .the pad is a non-absorbent baffle sheet appropriately placedin the pad. Such bafiles are generally a fluid-resistant film or sheetof thin material, such as those of the polyethylene type or the like.

However, since such fluid-resistant materials are usually quite smooth,there is a tendency for them to slide relative to the adjacent padsurface, particularly when the pad is deformed to fit the body surfaceto which it is applied. Consequently, the eifectiveness of the bafllesheet is largely lost in such instances, and there is produced anundesirable bunching and creasing of the fluidresistant film, which maycause considerable discomfort.

It is the principal object of this invention to provide an absorbent padwith a baffle sheet of fluid-resistant material in an improved mannerwhich avoids the above deficiencies. Other objects and advantages of theinvention will become apparent from the following disclosure of oneembodiment of the invention illustrated in the accompanying drawings,wherein:

Figure 1 is a plan view of the chosen embodiment, with portions of thepad partially displaced to better illustrate the detailed constructionof the pad;

Figure 2 is an enlarged sectional view, taken along the line 22 inFigure 1;

Figure 3 is a magnified, cross-sectional view of th bafile sheet used inFigures 1 and 2;

Figure 4 is an enlarged fragmentary view of the baflle sheet;

Figure 5 is a magnified, cross-sectional view of a modified form ofbafile sheet; and

Figures 6 and 7 are enlarged fragmentary views of further modificationsof the invention.

In, the making of an absorbent pad, bandage, sanitary napkin or thelike, it is very important that the absorbed fluid be essentiallyuniformly distributed throughout the pad, so that there is not asufiicient concentration of thefluid in any one area to strike throughthe pad. This is particularly important in connection with sanitarynapkins wherein discomfort and staining may readily result fromaconcentration of fluids on the outer surface of the pad.

Consequently, it is very desirable to provide some means to control theflow of fluids in an absorbent pad, so as to direct such fluids over amaximum area of the pad and to prevent the fluid from striking throughthe outer surface of the pad. In order to achieve these results, it hasbeen found to be advantageous to provide a bafiie sheet offiuid-resistant material at some portion of the pad which is spaced fromthe body side of the pad. However, the use of such baffle sheets haspresented other problems, particularly with respect to sanitary napkins.

The prior baffie sheets, which generally have been thin sheets ofwater-proof material, have been difficult to maintain in fixed relationto the pad body because of their inherently slippery characteristic.Consequently, with absorbent pads such as sanitary napkins, wherein thepad is deformed during use and is almost constantly subjected to movingforces, the bafile sheet slides relative to the pad and thereby losesmost of its effectiveness. Further, the thin and slippery baffle sheetoften becomes bunched together as it slides out of position and producesan undesirable bulkiness and creasing of the sheet which is verydiscomforting to the wearer.

The present invention is particularly directed to an absorbent padconstruction, including a battle sheet, which overcomes the abovedifficulties. More particularly, with reference to the drawings, it isseen that one embodiment of the invention is in the form of a sanitarynapkin 10, which includes a pad body 12 of absorbent material, a bafilesheet 14, a pair of side strips 16, and a gauze wrapper 18. Theillustrated pad body 12 is of a well known form of construction andcomprises an elongated body of comminuted fibrous material 2t),sometimes referred to as fluff, and a multi-ply sheet 22 of crepedwadding material disposed through an intermediatesection of thefluff,with the sheet 22 being embossed orcorrugated to provide longitudinallyextending channel portions for directing the flow of fluids lengthwiseof the pad.

A multi-ply creped tissue sheet 24 is disposed on each side of the flutlmaterial 20, and the opposite ends of the pad are pinched together toform a unitary structure of the fluid absorbent flufi and the sheets ofcreped tissue or wadding. Additionally, the sides of the pad areenclosed substantially the length thereof by the pair of side strips 16,which are also preferably of creped wadding material, wherein the linesof creping extend transversely of the pad.

The bafile sheet 14 is disposed on one surface of the pad body along asubstantial portion of the length, being generally coextensive in lengthwith the side strips 16. In the illustrated sanitary napkin, the bafflesheet is disposed on the side of the pad which will be the outer surfacewhen in use, and comprises a thin film of plastic material 14a having aweb of fibers 14b embedded therein on at least one side. The frictionalsurface afforded by the fibrous web 1412 is very advantageous inmaintaining the baffle in position in the pad. The engagement of thefibrous web with the creped tissue side strips 16 and with the gauzewrapper 18 is very effective in accomplishing this very desirableresult. Further advantages with respect to the prevention of slippage ofthe baffle sheet will be gained by including a fibrous 'Web on bothsides of the plastic film 14a, as shown in Figure 5 of the drawings. Inthe latter embodiment there is illustrated a baffie sheet 3t) comprisinga thin film 32 of fluid-repellant material bonded between two or morewebs 34 and 36 of fibers. Thus, there is not only provided a frictionalengagement between the upper surface of the baffle sheet and theoverlying portions of the side strips and gauze wrapper in the manner ofthe previously described embodiment, but there will also be frictionalcontact with the underlying pad body to further prevent slippage of thebaffle sheet. However, it is believed that the illustrated duplexconstruction of plastic film and fibrous web will suflice in mostinstances.

For sanitary napkin use, Where bulk is an important factor, it ispreferred that 'the embodiment of Figure 1 be employed, wherein thecomposite bafile sheet has an average thickness of between 2.0 and 6.0mils and a basis weight within the range of from about 3.0 to 40.0 lbs.per standard ream of 2880 square feet. The film should be from 0.15 to1.50 mils, preferably from about 0.33 to 0.75 mils, and the fiber Web onone side of the plastic film should preferably have a weight of fromabout 2.0 to about 20.0 lbs. per 2880 square feet. The fiber mayadvantageously be in the form of a creped tissue paper web, with apreferred crepe ratio for such web being from about 1.0 to 2.3. Thecreped web lends itself to flexing with the baflie sheet withoutseriously aifecting the bond therebetween, and also enhances thefrictional engagement between the baflie and the adjacent portions ofthe sanitary napkin. In one example, satisfactory use has been made of apolyethylene sheet having an average thickness of about 1.0 ml, andfaced with a creped tissue sheet having an uncreped basis weight of 7.6lbs. per 2880 square feet and a crepe ratio of 1.2, wherein the fibersof the tissue are partially embedded into the polyethylene sheet, asseen in Figure 3.

The smooth or film side 14a of the fiber-faced baffle sheet 14 isdisposed'in facing relation to the crepe wadding plies 24 on the outsideof the pad body, that is, the surface of the sanitary napkin which willbe disposed away from the body when inuse. The side strips 16 aredisposed in overlapping relation to opposite edge portions of thefibrous outer surface 14b of the baflle sheet, so that the frictionalengagement between the two fibrous surfaces will prevent relativemovement therebetween.

A gauze wrapper 18 or the like is disposed about the pad body,preferably with the overlapped portion of the wrapper overlying the sideof the pad.which includes the bafile sheet 14. This not only positionsthe wrapper fold away from the body of the wearer, which is desirablefor greater comfort, but also places a double thickness of the wrapperin position to provide a firmer engagement with the baflle coveredportion of the pad to prevent relative movement of the fiuid-repellantbaffle sheet.

It is seen, therefore, that there is provided an improved arrangementfor a bafiie sheet in an absorbent pad, which insures a firm positioningof the fluid resistant sheet relative to the pad. In the embodiment ofFigures 1 and 2, the fiber-faced baflle sheet 14 is frictionally engagedalong its marginal portions by the side strips 16, and is also heldacross its outer surface by means of the gauze wrapper 18.

It should be recognized, however, that while this particular arrangementis advantageous in connection with sanitary napkins, a more simplifiedconstruction may be employed without departing from the principles ofthe present invention. For example, the baflle sheet can be held inplace either by the side strips 16 alone, or by the gauze wrapper alone,where it is. desirable to eliminate one of the latter two elements.Further, the fiber-faced baffle sheet may be disposed internally of thepad body, at any desired location wherein the fiber surface of thebaffle sheet will frictionally engage other fibrous material in the padbody.

.It will also be apparent that other modified forms of absorbentbandages, sanitary napkins and the like, and other materials may be usedwithout departing from the principles of this invention. For example,while the baffle sheet 14 in Figure 1 is described as a plastic filmhaving a fibrous web embedded therein, a fluid-repellant plastic sheethaving a fibrous or other friction-producing covering which is bonded orotherwise secured in position on one or both sides of the sheet may beemployed in a manner similar to sheet 14 so as to secure the advantagesdiscussed above. Suchfi bflfil i i lus a d in l 4- wherein afluid-repellant sheet 40 is bonded to a Web 42 of fibrous material by aseries of adhesive spots 44 suitably spaced along the inner surface ofone of the materials. As in the previous embodiment, the fibrouscovering 42 may be of any form, a carded Web, a Woven or non-woven web,with the principal consideration being that it provide a frictionalsurface which is integral with the impervious baffle sheet 40 andprovide a minimum of additional bulk to the completed pad. It will beapparent that, if desired, a fibrous web may also be applied to theopposite surface of the baflle sheet 40 to provide a frictional surfaceon both sides thereof. It is intended, of course, that the baffle sheetthus formed will be used in the manner discussed above with respect toFigure 1.

Still another modified form of the invention is illustrated in Figure 7,where the bulk of a fiber-faced bafiie sheet embodying the invention isfurther reduced by utilizing spaced-apart fibrous appliques 50 on afluid repell ant film 52 to form a baffle 54. These fibrous spots may bebonded to the film 52 in any suitable manner, such as by the use of anadhesive or by embedding the fibers in the film in the mannerillustrated in Figures 3 and 5. The presence of the fibrous spots 50 onthe otherwise slippery film of material, which provides a fluidrepellantbaffle for the fluids in the pad, provides means for frictionallyengaging the overlying wrapper and/or side strips in the mannerdescribed above with respect to Figures 1 and 2.

Other modifications within the scope of the present invention willbecome apparent to those skilled in the art.

This application is a continuation of my co-pending application SerialNo. 522,092, filed July 14, 1955 and now abandoned, entitled SanitaryNapkin.

I claim:

1. An absorbent pad comprising a body of fluid absorbent, fibrousmaterial, a fluid resistant baffle sheet, and a fibrous wrapper disposedabout said pad body and battle sheet, said baffle sheet comprising a webof fibers embedded in a thin plastic film, said bafile sheet being sodisposed in said pad that frictional engagement is established betweenthe fibrous surface of said baflle sheet and an adjacent fibrous surfacein said pad thereby preventing relative sliding movement therebetween.

2. An absorbent pad comprising a body of fluid absorbent material, afluid-resistant baflle sheet disposed on the outer surface of said body,said baffle sheet comprising a web of fibers bonded with a thin plasticfilm and disposed with the fiber-faced surface facing outwardly of saidpad body, and a fibrous wrapper for said pad disposed about said pad andbaflie sheet, whereby the frictional engagement between said wrapper andthe fibrous surface of said baflie sheet maintains the latter inposition on the pad.

3. An absorbent pad comprising a body of fluid absorbent material, afluid-resistant baffle sheet disposed in the outer surface of said body,a fiber-faced surface portion provided for said baflie sheet by thebonding of fibers with said sheet, said baflie sheet being disposed withthe fiber-faced portion thereof facing outwardly of the pad body, and afibrous wrapper for said pad disposed about said pad body and bafflesheet, whereby the frictional engagement between said wrapper and thefibrous surface portion of said baffle sheet maintains the latter inposition on the pad body.

4. An absorbent pad comprising a body of fluid-absorbent material, afluid-resistant baflle sheet disposed on the outer surface of said body,a plurality of spaced-apart fibrous appliques bonded to the outwardlyfacing surface of said baflie sheet, a pair of fibrous side stripsextending along the edges of said pad body and having longitudinallyextending portions thereof disposed in overlying engagement withopposite edge portions of said baflle sheet a d W th a least one of saidfibrous appliques thereon,

and a Wrapper of fibrous material folded about said pad body inoverlying relation to said baffle sheet.

5. An absorbent pad comprising a. main body of fluid absorbent material,a fluid resistant baflle sheet disposed on the outer surface of saidbody, said baffle sheet comprising a web of fibers embedded in a thinplastic film and disposed with the smooth film side adjacent said padbody, and a pair of fibrous side strips extending along the edges ofsaid pad body and having longitudinally extending portions thereofdisposed in overlying engagement with opposite edge portions of saidbaflie sheet, whereby the engagement between said fibrous side stripsand the fibrous surface of the baflle sheet maintains the latter inposition relative to the pad body.

6. An absorbent pad including a body of fluid absorbent material havingan outer covering of creped tissue, a fluid resistant baffle sheetcomprising a sheet of creped tissue embedded in a thin plastic film anddisposed in covering relation to a substantial portion of the pad, withthe film side of said baflle sheet adjacent said pad body, a pair ofside strips of creped tissue extending along the edges of said pad bodyand having longitudinally extending portions thereof disposed inoverlying engagement with opposite edge portions of the tissue surfaceof said baffle sheet, and a wrapper of loosely woven fibrous materialfolded about said pad body in overlying relation to the crepe tissuesurface of said bafile sheet.

7. An absorbent pad including a body of fluid absorbent material havingan outer covering of creped wadding material, a fluid resistant bafflesheet comprising a thin film of plastic material and a web of loosecreped fibrous material bonded together in superposed relation, saidbaffle sheet being disposed in substantially covering relation to oneside of said pad body with said film facing said body, a pair ofsidestrips of creped wadding extending along the edges of said body andhaving longitudinally extending portions thereof disposed in overlyingengagement with opposite edge portions of the creped fibrous surface ofsaid baifle sheet, and a wrapper of loosely woven fibrous material forsaid pad body which is folded in overlapping relation on the sideincluding said baflie sheet, whereby the frictional engagement betweensaid side strips and said loose creped web on said bafile sheet andbetweensaid overlapping wrapper portions and said baffle sheet maintainsthe latter in position on said pad body.

8. An absorbent pad comprising an elongated main body of fluid absorbentmaterial, a fluid resistant baflie sheet substantially covering onesurface of said pad body, said baflle sheet comprising a loose, crepedweb of fibers embedded in a thin plastic film and disposed with thefibrous surface facing outwardly, said plastic film having a thicknesswithin the range of from about 0.15 mil to 1.50 mils, and said crepedweb having a basis weight of between about 2.0 lbs. and 20.0 lbs. perstandard ream of 2880 square feet before creping and a crepe ratio offrom 1.0 to 2.3, a pair of creped, fibrous side strips extending alongopposite edges of said pad body and disposed in overlying engagementwith opposite edge portions of said cover sheet, and a gauze wrapper forsaid pad comprising a web of loosely woven fibers folded 6 lengthwise ofsaid pad body and overlapped on said baflle sheet.

9. An absorbent pad comprising a body of fluid absorbent, fibrousmaterial, and a fluid-repellant baffle sheet, said baffle sheetcomprising a thin, fluid-repellant film disposed between a pair offibrous sheets and secured thereto, with the composite baffle sheetdisposed relative to said body of fibrous material so that frictionalengagement is established between at least one of the fibrous surfacesof said baflle sheet and an adjacent surface of the fibrous material insaid'body to prevent relative sliding movement therebetween.

10. An absorbent pad comprising a body of fluid absorbent material,fluid resistant baffle sheet, and a fluid permeable wrapper, said bafliesheet comprising a thin plastic film treated on at least one surfacethereof so as to increase its-frictional resistance, said baffle sheetbeing disposed covering relations to a substantial portion of said bodywith a treated surface of the sheet facing outwardly of said pad body,and said wrapper being disposed about said pad body and baflle sheet,whereby frictional engagement is provided between said wrapper and saidbaflle sheet to maintain the latter in position in the pad.

11. An absorbent pad including a body of fluid absorbent material havingan outer covering of creped tissue, a fluid-repellant balfie sheetcomprising a thin plastic film having a fibrous web attached to oppositesurfaces thereof, said baflle sheet being disposed on one side of saidpad body in covering relation to a substantial portion thereof, a pairof side strips of creped tissue extending along the edges of said padbody with longitudinally extending portions disposed in overlyingengagement with opposite edge portions of said baflle sheet, and awrapper of fibrous material folded about said pad body in overlyingrelation to said baffle sheet, whereby the frictional engagement of thefibrous surface of said baflle sheet with said pad body, said sidestrips, and said wrapper maintains said baflie sheet in positionrelative to said pad body.

12. A sanitary napkin comprisinga body of fluid absorbent, fibrousmaterial, and a fluid-repellant baflle sheet, said bafile sheetcomprising a thin, fluid repellant film having a web of fibers bonded toopposite surfaces thereof, with the composite baflle sheet disposedrelative to said body of fibrous material so that frictional engagementis established between at least one of the fibrous surfaces of saidbattle sheet and the fibrous material in said body to prevent relativesliding movement therebetween.

References Cited in the file of this: patent UNITED STATES PATENTS GreatBritain 1938 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No, 52,896,621 July 28, 1959 Kenneth Harw'ood.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

Celumn 3, line 21 for "m1" read m mil column 6, line 18, for "coveringrelation-s" r eed we in covering relation m Signed end sealed. this dayof 1960,,

(SEAL) Attest:

KARL I1 0 AXLINE ROBERT C. WATSON Attesiting Ofiicer Commissioner ofPatents

